The invention relates to an optical system comprising a semiconductor laser and an optical instrument for collimating the laser light, and with a holder which is connected to the collimating optical instrument being provided for the semiconductor laser.
Semiconductor lasers emit a strongly diverging beam of rays. In the use of semiconductor lasers, it is in many cases necessary to obtain a parallel beam of rays, for example, in video long-play systems, in digital optical recordings or in optical displacement measuring apparatus based on the interferometric principle. The strongly diverging light of the semiconductor laser must therefore be corrected by a collimating optical system. In this case, the lens system must be positioned very precisely in relation to the semiconductor laser component, with the focal point of the lens system having to be set within an exactitude range of a fraction of an .mu.m in relation to the semiconductor laser component.
An optical system of the aforementioned kind is known from the Federal Republic of Germany laid open patent application No. DE 2,734,257, in particular, FIG. 16. This principle arrangement does, however, not give any instructions for the precise setting and a suitable structural design for the system. A further optical system of the above-mentioned kind is known from the Federal Republic of Germany laid open patent application No. DE 3,142,630, in particular, FIG. 1. There, the laser component and the collimating optical instrument are accommodated, adjusted, optimized and rigidly connected by laser welding in a tube-shaped holder. This system does, however, have the disadvantage that a spring, a first adjusting ring, a further adjusting ring and a closure member are necessary, with the first adjusting ring and the closure member being rigidly connected by laser welding to the tube-shaped holder via blind hole bores. Accordingly, several parts are necessary in the assembly of the optical system, and three parts must be welded to one another.